The CA WA ESP AVGRUNTIME (average runtime) variable contains the average execution time in minutes of successful (COMPLETED) instances of a job.

The average runtime value is derived from the most recent elapsed times stored in the JOBSTATS data set. By default, 10 runs of a job will be used. (If there are less than 10 runs, then all the runs will be used.) To change the default value of 10, use the JINDEX(nn) parameter on the JOBSTATS init statement.